some epidemiological aspects of soil-transmitted helminthes in isfahan

epidemiological features of soil transmitted helminthes were studied in six villages in isfahan area. the mean overall prevalence of ascariasis and trichostrongyliasis were 91.5% and 70.9% respectively with higher infection rate among females. mean prevalence of trichuris and hymenolepis nana were 73.8% and 5.4% respectively. prevalences of ascaris and trichuris did not fluctuate very much in various ages but for trichostrongylus, infected was lower in 0-4 age group and h.nana was mostly found in lower age groups. in some villages 100% of both sexes were infected with one or more helminth parasites, and overall prevalence of infection was 97.3%. in all villages, it was found that a small proportion of inhabitants (12.5%) excrete a large proportion (43.3%) of total eggs of ascaris. prevalence and intensity of ascariasis established four years after therapy have shown that the group of population who had the highest prevalence before therapy, had the highest prevalence and intensity. the high proportion of infected cases with ascaris had less than 25000 eggs/gr of faeces and less than 50 worms. results of this study indicate once again the importance of intestinal helminthiasis in isfahan and also the possibility of reducing the transmission force by regular mass-chemotherapy of a small proportion of the inhabitants. more than 100 persons from each village who were infected with ascaris and some infected with other helminthes simultaneously, were treated a few days after examination, using pyrantel pamoate with a single dose of 10 mg/kg. body weight. tablets given to adults and suspension for children were taken in the presence of authors. a saline purge has also been administered to the patients treated who had constipation. a plastic pan containing 10% formaline solution and labeled with the name of the patient was also given to each patient after the drug was taken, in which all stools passed, up to 48 hours after treatment, were collected and all worms expelled during this period were removed and identified. treated cases were re-examined 2-3 weeks after the treatment and the cure rate established.